An agricultural baler is a trailed machine, typically towed behind agricultural vehicles such as tractors, used in agriculture for the purpose of forming bales of agricultural crop materials, such as straw, hay, silage or other biomass, produced during a harvesting or mowing operation. A baler typically comprises an infeed through which biomass is introduced into a bale-forming chamber. In the bale-forming chamber the biomass is generally compressed or otherwise treated to form bales. The completed bales are tied with twine or a similar lineal object or are packaged in another way to make them self-supporting. The bales are subsequently ejected by means of a discharge mechanism. Integrated attachment of labels to completed bales is considered a useful baler feature, thus providing for example bale identification and/or a record of bale properties, such as composition, weight, density and/or moisture level.
U.S. Pat. No. 7,717,149 discloses a device to apply an adhesive label around a moving lineal object such as twine used for tying bales. This device automates the otherwise manual process of applying labels to bales, and can operate on a continuous flow basis while the bales are moving through an agricultural baler. However, the presence of loose debris inside the baler environment and slack in the twine may interfere with the mechanical operation of such labeling device.